SU949346A1 - Device for light pulse registration - Google Patents

Description

The invention relates to technical physics and can be applied when measuring pulsed light or ionizing radiation fluxes in a wide dynamic range.

A device for detecting light pulses in a wide dynamic range is known, containing a photomultiplier tube, in the dynode circuit of which resistors are connected, from which the signals to the corresponding taps of the delay line Cl are removed.

A disadvantage of this device is the instability of sensitivity when exposed to destabilizing factors.

The closest in technical essence to the invention is a device for recording light pulses containing a photomultiplier and an automatic system

adjusting the gain, the input of which is connected to the anode of the photomultiplier and the output to the input of the resistive voltage divider, the outputs of which are connected to the dinodes of the photomultiplier 2,

A disadvantage of the known device is the limited functionality and accuracy of the measurement.

The purpose of the invention is to expand the functionality and increase the accuracy of measurement.

Claims (2)

This goal is achieved by having a device for detecting light pulses containing a photomultiplier and an automatic gain control system, the input of which is connected to the anode of the photomultiplier and the output to the input of a resistive voltage divider, the outputs of which are connected to the dynoids of the photoelectric multiplier i The integrator and separation capacitors are introduced through which the dynoids of the photomultiplier tube are connected to the integrator input. The drawing shows the block diagram of the device. The device for recording light pulses contains a photomultiplier 1 and an automatic gain control system 2, the input of which is connected to the anode 3 of photomultiplier 1, and the output with resistive divider k. The outputs of which are connected to the dynodes 5 of photomultiplier 1. Dynamo 5 connected to the input of the integrator 6 via coupling capacitors 7; As an integrator, it is advisable to use a capacitive divider from capacitors 8, shunted by reverse-biased voltage diodes 9 which is set via resistor 10 to the source. The automatic gain control system 2 may contain a control radiation source 11, illuminating the photocathode 12 of the photomultiplier 1, the filter 13, whose input is connected to the anode 3, and the output to the comparison unit H, the output of which is connected through a controlled voltage source 15 with a divider A load 16 is connected to the anode 3. The device operates as follows. The control source 11 emits a constant stream of light to the photocathode 12, which is converted into electric current by a photomultiplier 1. The anode 3 current of the photomultiplier 1 passes through a 13 p filter into the comparison unit I, where the value is compared with the reference current. If there is a mismatch between them, the mismatch signal is fed to an adjustable voltage source 15, which changes the supply voltage on the photomultiplier 1 until the anode current value of photomultiplier 1 becomes equal to the reference current. Thus, the magnitudes of the sensitivity of the photomultiplier 1 at the anode output 3 n are kept constant under the influence of various destabilizing factors. 4 The pulsed radiation flux decreases and the photocathode 12 of the photoelectron suppressor 1, which converts its current impulse, the shape of which corresponds to the shape of the light pulse is removed from the load 16, while the Iltre 13 does not transmit a pulse to the comparison unit Ik, which ensures stable operation of the controlled source 15 at registration of pulse signals. The current pulses from each dynode 5 of the photomultiplier 1 are fed to the capacitors 8 of the integrator 6 If the duration of the light pulse T is significantly less than the constant integration equal to the product Cj-jRj SS °, the current pulses are integrated on this capacitor G К K, | C, .4% 5 l Cj capacitance, C, i of the i-th capacitor 8, the resistance of the i-ro resistor 10. In this case, each dynode 5 represents a current generator fault connected to integrator 6, and the total current of the dynode 5, charging, rator 6, is practically (with an error of 10) equal to the anode current 3 and subsequently stabilized as the anode current. At the end of the light pulse, the voltage amplitude at the output of the integrator 6 (output 1) is a function of illumination (integral of the brightness of the light). In order to obtain a linear dependence of the output voltage of the integrator 6 against the illumination, the integrator 6 can be made in the form of an integrating RC-chain. In order to obtain a nonlinear dependence or split the range into a number of subranges, it is advisable that integrator 6 be in the form of a capacitive divider from capacitors 8 shunted by diodes E, while the voltage from the mid-points is proportional to the luminescence, and from OUT 1 it is quasi-log-dependent on the latching. The present invention allows simultaneous measurement of luminance and illumination of a light pulse with high accuracy and noise immunity. An apparatus for detecting light pulses, comprising a photomultiplier and an automatic gain control system, the input of which is connected to the anode of the photomultiplier and the output is connected to the input of a resistive voltage divider, the outputs of which are connected to the dynoids of the photomultiplier, characterized in that, for the purpose of expansion its functionality and accuracy, an integrator and separation capacitors are introduced into it, through which the photoelectron dynoes will multiply Ate connected to the input of the integrator. Sources of information taken into account during the examination 1. USSR author's certificate number 44b770, cl. G 01 J 1/00, 197. 2. USSR author's certificate number 795202, cl. Q 01J 1/20, 1981 (prototype).